Differential brake



H. F. JOHNSON.

' DIFFERENTIAL BRAKE.

APPLICATIONHLED NOV 1. I99. 1,393,135. Patented Oct. 11, 1921.

' 2 suns-sum 1. 29 14 5 f5 f6 78 7 25 fr um r in In [GI/In fa v [lop/Ago f7 .lomvsoy .a'agy, v

H. F. JOHNSON.

DIFFERENTIAL BRAKE.

APPLICAHON man NOV- 7, 1919.

1,893,135. Patented 001 11,1921.

2 SHEETS-SHEET 2.

llllll 1m HIM ill rrich.

I'L'OVIABD I. JOHNSON, GIG CLEVELAND, SE10, ASSIGNGR T THE EOEVNING COIM- PAI-JY, 0F CLEVELAND, GHZO, A. CGRPOR-ATION 035 015510.

DIFFERENTIAL BRAKE.

Specification of Letters Patent.

Patented (lot. 11, 1921.

Application filed November Y, 1819. Serial No. 338,454.

T 0 all whom it may concern:

lie it known that I, Plowano i JOHNSON, a citizen of the United States, resident of Cleveland, county oil. Cuyahoga, and State or" ()hio, have invented new and useful Iniprovelnents in. Differential Brakes, 0'f \l11l1 the tollowinp is a specificatiointhe prlnciple of the invention being herein explained and the best mode in which I have contemplated applying that principle, so as to distinguish it from other inventions.

l'dv invention relates to dilterential brakes. Particularly the invention relates to abrake of this chdracter which will act automatically to release or set a brake band upon the reversing of the direction of inovernent of the power-driven mechanism to which the bralre drum is connected. My improved brake is of general application, but I shall illustrate the principle thereof by means of showing and describing embodiment of the same as applied to hoisting apparatus.

The annexed drawings and the following description set forth in detail. certain means embodying my invention, the disclosed means, liowever constituting but one of the various mechanical forms in which the principle of the invention. may he applied.

In said annexed drawings:

Figure 1 represents a side elevation of my improved brake applied to hoisting apparatus. fragmentary portions of the latter only being shown, the view showing the position of the several parts during the hoisting' of the load; Fig. 52 represents a plan *iew taken in the planes indicated by the lines llli Fig. 1.

Fig. 3 represents an elevation-oi the parts shown in Fig. 1 when the brake is set to suspend the load; and Fig. represents an elevation of the same parts when the brake is released so that the load may be lowered.

Referring; to the annexed drawings, there is indicated by the ordinal 1 a drum upon which a hoisting" cable is adapted to be wound to lift a load by means of cooperatmechanism, not shown. di un 1. is the usual brake drum 2, and cooperating therewith is a brake band 3. Se cured to the drum 2 is a gear member 4 adapted to be driven by pinion 5 upon a shaft 6 which is driven by any suit able source of power.

A be id lever 7 is pivotally mounted at one Secured to the a mounted 1 end upon a rod 12 suitably supported in the main frame 29. There are provided cooperating parts for the hand lever 7, such as the reciprocable member 8 formed with an inner catch portion 9 ada Jted to cooperate with the notches 11 formed in a suitably supported frame member 10.

Pivotally niounted upon the rod 12 is a rocking member 13 formed with two forwardly projecting arms The outer free end of said arms 14 are intersected by a pair ofpivotally mounted pins 15. Said pins 15 are also pivotally mounted in one end 01" a pair of links 16. These links 16 are pivotally mounted at their other ends on a pin 17 secured to one end of the brake band A second pair of links 18, of angular fornation, as plainly shown in Figs. 1. and l, are pivotally secured at one end to transversely disposed block 19 mounted on a pin 20. Secured in this block 19 and centrally thereof by means of the pin 20 and nut 21, is a longitudinally disposed tongue ieinbe'r 21, to the forward end of which is pivotally scored the other end of brake band 3 by means of the pin This pair of angular links 18 are pivot-ally connected my th aforementioned pins 15, and at their an es, to the arms 14 ot the reciting rneinbe 13 and also to the pair of links 16. The other ends oi the pair of links 18 are pivotally secured by means of a pin 23 to an arm 2 which is pivotally secured'by a pin 26 to a hug formed upon the hand lever 7, the intermediate turnbuckle being also provided for longitudinal adjustment.

Suitably mounted in the main frame 29 are a pair of stop members 27 and 28. An adjustable range oi action for the elements controlled by said stop membersis secured by means of the respective screws 30 and 31, as plainly shown and as will be readily understood.

The automatic action of my differential brake depends upon the functioning; of

special means which, when the brake drum 2 tends to reverse lts direction of movement,

will bring the ends of the brake band 3 more closely together or more widely space them.

l mentioned in tances from a pivotal. axis. In other words, assuming that the brake is loose as shown in Fig! 1, when hoisting is being ei ected, now

desired to sus end the load, and the it it is engine is shut off or the clutch thrown out,

' and no manipulation of a brake takes place,

' downward pull would continue until it is terminated by the stop member 2", the sillcient gripping of the brake drum 2 by th band having taken place in the meanwhile for the reason now to be given. This reason is, that the links 18 would have pivot-ally moved upon the pin 23 and the pair of pins 15 to pull down the upper end of the brake band secured to the pin 22. Due to the comparatively greater movement of the outer end of the links 18, as compared with the movement of the section containing the pins 15, the upper end of the brake band 3 would have moved down a greater distance than the lower end thereof, and the result is indicated in 3, where the brake is set to prevent the reverse action of the drum 2 and thus to suspend the load.

If it is desired to raise the load, the parts being set as shown in Fig. 3, the movement of the drum 2 in the direction of the arrow indicated in Fig. 1 will cause the upper'end of the brake band to be raised, which will raise the pins 15 and consequently the linlr 16, Again, however, the movement of the upper end of the brake band will be proportionately greater than the lower end, resulting in greater spacing of said two ends of the band a consequent loosening drum 2 or the from the frictional contact of the band 3, other than that occasioned by the weight of the band itself. This last ctional contact isnot enough to retard the free movement of the drum 2 and the continued movement of the band 3 is prevented by the stop member 28,

It it is desired to lower the load the drum 2 positively is released from the frictional contact of the band 8 shown in 3 by means of the actuation of the hand lever 7 from the position shown in Fig. 3 to that shown in 'g. a, or any other suitable intermediate position, This actuation of the iand lever 7 results in a swinging of the ends of the links 18, pivoted upon the pin raising the pin 20 and I about the pins 10, L consequently the upper end or" the brake band 8 until the member 13 strikesthe stop 27. This is accomplished with little or no movement upon the part of the lower end of tion t is necessary during the hoisting or en d 19: is to shut oil the engine or thixw out the clutch, instead of it being eccssary to use both hands,as heretofore, to shut oil the engine and to manipulate the alre.

j u sted,

s desired, by means of the turn buclr e 2 and the screws 30 and 31.

hat i claim is:

1. is. differential brake, comprising a br ke drum; a brale band; and means for itching and releasing said brake band tomatically, including a pivotally supported member, a link' pivotally secured to said member and pivotally secured to one end of said brake band, and a second link pivotally secured to the other end of said brake band and pivotally secured to said iinl: intermediately of the two pivotal ections ot the latter. A dillerential brake, comprising a e drum; a brake band; and means for 4 and releasing said brake band automatically, including a link pivotally mounted at one end, means limiting the cunt of said pivotal movement, said link being pivotally secured at its other end to one end or said brake band, and a second link pivotally secured at one end to the other end of said hrake band and pivotally secured to said first link intermediately of the ends of the latter.

3. l i hoisting apparatus, the combination oi? a frail e; a cable drum; a brake drum secures to the latter )ower means for rotat-- ing said cable lrum; a brake band; a pin; snppr sting means for said pin mounted on said frame so as to have a reciprocating movement relative to the latter; a link pivotally secured at one end to said pin and pivotally secured at the other end to one end of said brake band; and a second link pivotally secured at one end to said first link intermediatcly of the ends of the latter and pivotally secured at its other end to the other end of said brake band.

ln hoisting apparatus, the combination of a frame; a cable drum; a brake drum secured to the latter; power means for rotating said cable drum; a brake band; a pin sun orted by said frame and free to have a The range of movement can be adbrake band; a second link pivot-ally secured to said first link at the angle thereof and pivotally secured to the other end of said brake band; a rock arm pivotally mounted in said frame and pivotally secured at one end to said two links; and stop members limiting the movement in both directions of said rock arm.

5. In hoisting apparatus, the combination of a frame; a cable drum; a brake drum secured to the latter; power means for rotating said cable drum; a brake band; a notched member secured to said frame; a hand lever pivotally mounted at one end in said frame and adapted to cooperate with said notched member for setting or releasin an arm adjustable in length pivotally secured at one end to said hand lever; a pin mounted in the free end of said arm; a rock arm pivotally mounted in said frame; stop members limiting the movement in both directions of said rock arm; a link pivotally secured to one end of said rock arm and pivotally secured to one end of said brake band; a second link pivotally secured to the other end of said brake band, pivotally secured intermediately its ends to said rock arm and said first link and pivotally secured to the pin mounted in the free end of the above mentioned arm.

Signed by me this 21st day of October HONARD F. JOHNSON. 

